1. Field of the Invention
The present invention relates to a packaging processing apparatus used in a packaging machine.
2. Prior Art
In a typical packaging machine, container holding means are continuously conveyed at a constant speed and uniform spacing along a circular or circular-arc-shaped path, and packaging processing such as filling with a liquid-form substance into containers held by the container holding means, etc. is performed while the container holding means are being conveyed.
Japanese Patent Application Laid-Open (Kokai) No. 10-305802 discloses such a packaging machine. This packaging machine includes a continuously rotating table and an intermittently rocking table. The continuously rotating table is provided on its circumference with numerous grippers that are arranged at uniform intervals. The intermittently rocking table is installed above the continuously rotating table and is raised and lowered at a specified timing. To the circumference of the intermittently rocking table, numerous filling nozzles and capping heads are attached at the same pitch as the pitch of the grippers.
In this packaging machine, containers are continuously conveyed by the grippers. During this conveying action, the intermittently rocking table is raised and lowered and performs a horizontal reciprocating motion at a specified timing. During the advancing motion of the table (when the table swings in the direction same as the direction of movement of the grippers, this is called the advancing motion; and when the table swings in the opposite direction, it is called the return motion), filling processing and capping processing are performed while the filling nozzles and capping heads are lowered and caused to follow the conveying motion of the containers. Then, when the specified advancing motion reaches its end, the filling nozzles and capping heads are raised, the table makes a return motion, and then the table returns to the starting point of its advancing motion.
In this packaging machine, in order to raise and lower the filling nozzles and capping heads and cause these elements to perform a reciprocating motion, the intermittently rocking table is used that is supported by a suspension rod around which a compression spring is wound, an upper supporting plate on which the suspension rod is installed is attached to a rising-and-lowering shaft which passes through the center of the continuously rotating table, and the rising-and-lowering shaft is raised and lowered by a first cam. In addition, a retaining plate that is engaged with the suspension rod is installed on a hollow shaft (through which the rising-and-lowering shaft is passed), and the hollow shaft is caused to make a reciprocating pivot motion by a second cam.
As seen from the above, the rising-and-lowering and reciprocating swing mechanism of the filling and capping apparatus of the above-described packaging machine is extremely complicated. Accordingly, it not only increases the cost but also causes a conspicuous drop in maintenance and cleaning characteristics. Furthermore, the rising-and-lowering driving section supports not only the intermittently rocking table but also the rising-and-lowering shaft, upper supporting plate, suspension rod and compression spring, and further it must raise and lower these elements. Consequently, if the load is taken into consideration, the structure must be strong and durable, but this increases the size of the apparatus unavoidably.
Accordingly, the present invention is to solve the above-described problems with a packaging processing apparatus that performs packaging processing such as filling, etc. in a packaging machine.
In other words, the object of the present invention is to provide an improved packaging processing apparatus that has a simplified mechanism for its rising-and-lowering and reciprocating swing motions, thus reducing the cost, improving the maintenance and cleaning characteristics and further reducing the size of the apparatus.
The above object is accomplished by a unique structure for a packaging processing apparatus used in a packaging machine, the packaging machine comprising:
a rotating body (sprocket, for instance) that is attached to a rotating shaft connected to a driving means, the rotating body being rotated at a constant speed on a horizontal plane, and
a plurality of container holding means (gripper pairs) that are, upon rotation of the rotating body, moved continuously at a constant speed and a uniform spacing along a circular or circular-arc-shaped traveling path around a circumference of the rotating body; and
specified packaging processing operations are performed, by a plurality of packaging processing means (filling nozzles, for instance), on containers during a movement of respective container holding means along the circular or circular-arc-shaped traveling path, the packaging processing means being arranged in a form of a circular arc so as to correspond to the container holding means at a same pitch as the containers held by the container holding means and performing a synchronous movement for a specified angular range at a same speed as the containers held by the container holding means, wherein
the packaging processing apparatus is comprised of:
(i) a pivot member which is disposed above the rotating body, the pivot member being concentric with the rotating shaft and being connected to a driving means so that the pivot member performs a reciprocating pivot motion on a horizontal plane,
(ii) a rising-and-lowering assembly which is disposed on the pivot member so that the rising-and-lowering assembly is raised and lowered and pivoted together with the pivot member,
(iii) a circular first raising-and-lowering cam which is disposed concentrically with the rotating body and rotated together with the rotating body,
(iv) a circular-arc-shaped second raising-and-lowering cam which is provided concentrically with the rotating body above the rotating body,
(v) a rolling member (cam roller) which is attached to the rising-and-lowering assembly and rolls over cam surfaces of the first and second raising-and-lowering cams so that the rising-and-lowering assembly is raised and lowered at a specified timing, and
(vi) a plurality of packaging processing means which are disposed on the rising-and-lowering assembly and perform a reciprocating motion as the pivot member pivots; and
the rising-and-lowering assembly is subjected to an action of the second raising-and-lowering cam during an advancing motion of the pivot member and is subjected to an action of the first raising-and-lowering cam during a return motion of the pivot member.
In this structure, when the pivot member is moved during its pivot motion in the same direction as the direction of movement of the container holding means, this is referred to as an advancing motion; and when the pivot member is moved in the opposite direction, then this is referred to as a return motion.
The rising-and-lowering assembly is lowered and raised during the advancing motion of the pivot member and is maintained in a raised position during the return motion of the pivot member.
More specifically, the first raising-and-lowering cam is provided with a cam surface that has a uniform height and a plurality of recessed portions that are formed at predetermined angular intervals, and the second raising-and-lowering cam is provided on both sides thereof with cam surfaces that has substantially the same height as the cam surface of the first raising-and-lowering cam and is further provided with a lower-height cam surface between the cam surfaces on both sides.
With this structure, a setting is made so that during the advancing motion of the pivot member, the rolling member is positioned in one of the recessed portions of the first raising-and-lowering cam and rolls over the cam surface of the second raising-and-lowering cam, thus allowing the rising-and-lowering assembly to be lowered and raised; and during the return motion of the pivot member, the rolling member rolls over the cam surface of the first raising-and-lowering cam, thus allowing the rising-and-lowering assembly to be maintained in the raised position.
In the present invention, the packaging processing means are, for instance, filling nozzles for a liquid-form substance (thus, the packaging processing apparatus is a liquid filling apparatus). However, the packaging processing means can be capping heads, gas substitution nozzles, inner sealing heads (heads that heat-seal aluminum foil on the mouths of spouts), and the like.
Furthermore, the present invention can be used not only in cases where the container holding means (grippers) are disposed at equal intervals on the circumference of a continuously rotating body (rotating table) as in the above-described conventional machine (with the container holding means moving over a circular traveling path) but also in cases where, for example, the rotating body is a continuously rotating sprocket, and an endless chain on which the container holding means (grippers) are disposed at equal intervals is mounted on the sprocket (with the container holding means moving over a circular-arc-shaped traveling path at the location of the sprocket). Furthermore, the present invention is applicable to cases where the containers (bags) are inserted into retainers and continuously conveyed (in this case, the retainers are the xe2x80x9ccontainer holding meansxe2x80x9d).